Vasculature navigation systems and methods

ABSTRACT

A vasculature navigation system may include a dilator having a proximal end and a distal end located opposite the proximal end, the dilator comprising a guidewire lumen extending between the proximal end and the distal end, the dilator defining a proximal portion and a distal portion located opposite the proximal portion. In some embodiments, the vasculature navigation system also includes an access port located at the proximal end of the dilator, a distal port located at the distal end of the dilator, and a hemostasis valve coupled to the proximal portion of the dilator. The hemostasis valve may be configured to control fluid flow between the proximal portion and the distal portion. In some embodiments, a flush port is coupled to the proximal portion of the dilator and located distal to the hemostasis valve, and the flush port is coupled to a fluid supply source.

CROSS-REFERENCE TO RELATED APPLICATIONS

The entire contents of the following application are incorporated byreference herein: U.S. application Ser. No. 17/401,996; filed Aug. 13,2021; and entitled VASCULATURE NAVIGATION SYSTEMS AND METHODS.

The entire contents of the following application are incorporated byreference herein: U.S. application Ser. No. 17/107,791; filed Nov. 30,2020; issued as U.S. Pat. No. 11,090,466 on Aug. 17, 2021; and entitledCATHETER SYSTEMS AND DEVICES FOR ACUTE ISCHEMIC THROMBECTOMY.

BACKGROUND

Various embodiments disclosed herein relate to catheter systems. Certainembodiments relate to catheter systems for performing a thrombectomy oran embolectomy.

Mechanical thrombectomy is a procedure that removes clots throughendovascular intervention to restore blood flow to the brain duringacute ischemic stroke. Acute Ischemic Stroke (“AIS”) can be caused bythrombus, embolus or other occlusions in regions of the internal carotidartery such as the Petrous segment, Cavernous segment and/or Cerebralsegment, or the middle cerebral artery, such as the MCA bifurcation, theM1 segment, and/or the M2 segment. Approaches for performingthrombectomy or embolectomy to treat AIS include accessing thevasculature and navigating a balloon guiding catheter to the carotidartery at a location upstream from the occlusion, typically at aproximal location in the artery such as the cervical segment of the ICA.After the balloon is inflated to provide antegrade blood flow cessation,retrieval devices can be passed through the balloon guiding catheter toretrieve the embolus. Thrombectomy tools such as stent retrievers,aspiration catheters, or both can be delivered directly to the embolusthrough the guiding catheter to complete the retrieval process, afterwhich the balloon is deflated and the retrieval and guide catheters areretracted to the access point.

Navigation through the vasculature to the face of the occlusion canoften be difficult, due to the distal edge of a balloon guiding catheteror another primary device (e.g., sheath, aspiration catheter, otherguide catheter, and the like) becoming “stuck” or stopped on the ledgeof a blood vessel, such as the ostium of the ophthalmic artery, or bycarotid plaque or lesions elsewhere in the vasculature, which is alsoknown as “shelf effect.” Some efforts have been made to reduce shelfeffect through the use of microcatheters, where the primary device istracked over a microcatheter, and the microcatheter is tracked over aguidewire. However, shelf effect may still be an issue when there is asignificant difference between the inner diameter of the primary deviceand the outer diameter of the microcatheter, as the gap between themicrocatheter and the primary device may still become “stuck” duringnavigation through the vasculature.

For example, stroke aspiration catheters tracked over existingmicrocatheters can still become stuck or stopped on the ledge of theostia, such as the ostium of the ophthalmic artery, when the ledge ofthe stroke catheter makes contact with the edge of the arterial origin.As such, further advancement of the catheter through the vasculature maybecome much more challenging or impossible when using existingtechnologies.

Numerous attempts have been made to develop solutions to reduce theshelf effect issues faced by clinicians performing various procedures.For example, U.S. Pat. No. 7,641,645, assigned to AngioDynamics, Inc.,of Queensbury, NY, USA, discloses a “Combination Thrombolytic InfusionCatheter and Dilator System” that includes an internal dilator removablycoupled to a drug delivery catheter. However, the infusion catheter isintended to administer lytic agents to grafts that are used to connect avein to an artery for bypass and/or dialysis procedures, rather than totreat AIS via an intercranial procedure, such as a thrombectomy.

Another example of an attempt to reduce shelf effect is disclosed inU.S. Pat. No. 10,682,493, assigned to MicroVention, Inc., of AlisoViejo, CA, USA. The '493 patent discloses “Intravascular Treatment SiteAccess” via a device intended to reduce the gap between a catheter and aguidewire. The patented device includes a guidewire with an enlargeddistal portion. The device does not include a microcatheter, dilator, oranother intermediary device intended to track over the guidewire betweenthe guidewire and an outer catheter.

Yet another example is the “Transcarotid Neurovascular Catheter”disclosed in U.S. Patent Application No. 2020/0171277, assigned to SilkRoad Medical, Inc., of Sunnyvale, CA, USA. The claimed device comprisesa neurovascular catheter designed for direct insertion into the carotidartery. As a result, the claimed device requires a working lengthsignificantly shorter than the working length required for acatheter/internal device (e.g., microcatheter, dilator, or the like)designed for insertion in a femoral artery or other artery locatedfurther from the brain than the carotid artery. In addition, like the'493 patent, the '277 application discloses a neurovascular catheterwithout an internal/intermediary device.

U.S. Pat. No. 9,408,667, assigned to Olympus Corporation of Tokyo,Japan, discloses a “Guide Sheath and Guide Sheath System.” The patentedsheath comprises a tubular sheath designed for providing anchoringsupport upon insertion into the pericardial cavity. Rather than aidingin navigation through the vasculature, the guide sheath is intended tohold the system in position.

Another device designed to reduce shelf effect is the “WedgeMicrocatheter” produced by MicroVention, Inc. The device includes anenlarged bulb segment and claims to “optimize SOFIA 6F Catheternavigation past tortuous bifurcations allowing SOFIA 6F Catheter toaccess extremely challenging occlusion locations.” As indicated, theMicroVention device is specifically described for use with the SOFIA 6Fcatheter, which severely limits the utility of the device. A devicedesigned for use with any stroke catheter would greatly improve upon theutility currently provided by the MicroVention device.

The Tenzing 7 Delivery Catheter, produced by Route 92 Medical of SanMateo, CA, USA, is another device aimed at reducing shelf effect. Thetapered delivery catheter is designed to “deliver intermediate cathetersto the face of an embolus without crossing.” Because the deliverycatheter is specifically designed to “not disturb” the embolus, it isnot designed for use over a guidewire, as guidewires generally contactthe embolus.

SUMMARY

The disclosure includes a catheter system comprising an elongated accessassist device having a proximal end and a distal end located oppositethe proximal end, the elongated access assist device comprising aguidewire lumen extending between the proximal end and the distal end,the elongated access assist device defining a proximal portion and adistal portion located opposite the proximal portion. The cathetersystem may also include an access port located at the proximal end ofthe elongated access assist device, the access port configured toreceive a guidewire, and a distal port located at the distal end of theelongated access assist device, the distal port configured to furtherreceive the guidewire. In many embodiments, the catheter system furtherincludes a hemostasis valve coupled to the proximal portion of theelongated access assist device, the hemostasis valve configured tocontrol fluid flow between the proximal portion and the distal portion,and a flush port coupled to the proximal portion of the elongated accessassist device and located distal to the hemostasis valve, wherein theflush port is configured to couple to a fluid supply source. Thecatheter system may include a tapered portion defining at least part ofthe distal portion of the elongated access assist device, wherein anouter surface of the tapered portion tapers downward toward the distalend, and a plurality of microperforations coupled to at least the distalportion of the elongated access assist device, the plurality ofmicroperforations configured to release fluid from the fluid supplysource.

In some embodiments, the hemostasis valve is integrated into theelongated access assist device. The fluid supply source may include asupply of at least one of saline and contrast dye. In many embodiments,the guidewire lumen is configured to receive the guidewire such that theguidewire extends from the access port of the elongated access assistdevice through the distal port of the elongated access assist device.

The tapered portion may define a length of less than or equal to twentycentimeters. In many embodiments, the plurality of microperforations aresubstantially evenly spaced and dispersed across the tapered portion.The plurality of microperforations may be configured to facilitate asubstantially continuous release of fluid.

In some embodiments, the catheter system further comprises a firstmarker band coupled to a distal tip of the tapered portion, wherein thefirst marker band comprises a radiopaque material. The system mayinclude a second marker band coupled to the elongated access assistdevice proximal to the tapered portion, wherein the second marker bandcomprises radiopaque material. In some embodiments, the radiopaquematerial comprises at least one of iridium and platinum.

The system may further comprise a neurovascular sheath sized andconfigured to slideably receive at least a portion of the elongatedaccess assist device, where the neurovascular sheath defines an innerdiameter and the elongated access assist device defines an outerdiameter. The outer diameter may be about 90% of the inner diameter. Theinner diameter of the neurovascular sheath may define a diameter ofabout 0.088 inches and the outer diameter of the elongated access assistdevice may define a diameter of about 0.079 inches.

In some embodiments, the system further comprises a neurovascularaspiration catheter sized and configured to slideably receive at least aportion of the elongated access assist device, where the neurovascularaspiration catheter defines an inner diameter and the elongated accessassist device defines an outer diameter. The outer diameter may be about90% of the inner diameter. The inner diameter of the neurovascularaspiration catheter may define a diameter of about 0.072 inches and theouter diameter of the elongated access assist device may define adiameter of about 0.065 inches.

In some embodiments, the tapered portion defines a proximal outerdiameter of about 0.068 inches, a proximal inner diameter of about 0.02inches, a distal outer diameter of about 0.023 inches, whereby thedistal outer diameter is located distal the proximal outer diameter, anda distal inner diameter of about 0.018 inches, whereby the distal innerdiameter is located distal the proximal inner diameter. In someembodiments, the tapered portion defines a symmetrical conical shape.The tapered portion may define an asymmetrical conical shape.

In many embodiments, the system further comprises a hydrophilic coatinglocated on at least a portion of an exterior surface of the elongatedaccess assist device. The elongated access assist device may define aworking length of about 133 centimeters. The elongated access assistdevice may define a working length of about 91 centimeters. In someembodiments, the distal port defines a guidewire lumen diameter of about0.02 inches.

The disclosure includes a vasculature navigation system comprising adilator having a proximal end and a distal end located opposite theproximal end, the dilator comprising a guidewire lumen extending betweenthe proximal end and the distal end, the dilator defining a proximalportion and a distal portion located opposite the proximal portion. Thesystem may further comprise an access port located at the proximal endof the dilator and configured to receive a guidewire, and a distal portlocated at the distal end of the dilator, the distal port configured tofurther receive the guidewire. In some embodiments, the sy stem includesa hemostasis valve coupled to the proximal portion of the dilator, thehemostasis valve configured to control fluid flow between the proximalportion and the distal portion. The system may include a flush portcoupled to the proximal portion of the dilator and located distal to thehemostasis valve, wherein the flush port may be configured to couple toa fluid supply source. The system may also include a tapered portiondefining at least part of the distal portion of the dilator, wherein anouter surface of the tapered portion tapers downward toward the distalend.

In many embodiments, the vasculature navigation system further comprisesa plurality of microperforations coupled to at least a portion of anexterior surface of the dilator, the plurality of microperforationsconfigured to release fluid from the fluid supply source. The pluralityof microperforations may be configured to release a substantiallycontinuous flow of fluid from the fluid supply source. In someembodiments, each microperforation of the plurality of microperforationsdefines a diameter of about 0.01 inches on the exterior surface of thedilator. Each microperforation of the plurality of microperforations maydefine an aperture.

The fluid supply source may be pressurized to an extent sufficient toenable propulsion of the dilator upon release of fluid via the pluralityof microperforations. In some embodiments, the fluid is pressurizedwithin the dilator to the extent sufficient to enable propulsion of thedilator as the fluid is released from the plurality ofmicroperforations. The fluid supply source may comprise a supply ofsaline.

In some embodiments, the plurality of microperforations is arranged in aspiral configuration around the exterior surface of the dilator. Eachmicroperforation of the plurality of microperforations may be evenlyspaced from an adjacent microperforation. The plurality ofmicroperforations may be coupled to the proximal portion of the dilator.

In many embodiments, the system further comprises a hydrophilic coatinglocated on the distal portion of the dilator, wherein the hydrophiliccoating is configured to reduce friction between the dilator and apatient's vasculature. The plurality of microperforations and thehydrophilic coating may enable navigation of the dilator through apatient's vasculature by reducing friction between the dilator and thepatient's vasculature. In some embodiments, the plurality ofmicroperforations may be located proximal to the hydrophilic coating,and the fluid released from the plurality of microperforations may beconfigured to flow over the hydrophilic coating.

In some embodiments, the dilator comprises a reinforcement structurelocated within a wall of the dilator, the reinforcement structuredefining a coil shape. The reinforcement structure may be located withinsubstantially an entire length of the dilator. In some embodiments, thereinforcement structure comprises a round wire.

The dilator may be configured to be received by a primary device suchthat at least the tapered portion of the dilator extends distal a distalend of the primary device, and the dilator may comprise a hydrophiliccoating configured to reduce friction between the dilator and theprimary device.

The disclosure may include a method of navigating a dilator through apatient's vasculature, and the method may comprise inserting, via anaccess site, the dilator into the patient's vasculature, wherein thedilator comprises an access port located at a proximal end of thedilator and configured to receive a guidewire, a distal port located ata distal end of the dilator and configured to further receive theguidewire, a hemostasis valve coupled to a proximal portion of thedilator and configured to control fluid flow between the proximalportion and a distal portion, a flush port coupled to the proximalportion of the dilator and configured to couple to a fluid supplysource, and a plurality of microperforations coupled to an exteriorsurface of the dilator. In some embodiments, the method furthercomprises pressurizing the fluid supply source to a pressure sufficientto enable propulsion of the dilator and releasing, via the plurality ofmicroperforations, at least a portion of fluid from the pressurizedfluid supply source, wherein releasing at least the portion of fluid isconfigured to enable propulsion of the dilator through the patient'svasculature. The method may further comprise inserting, over thedilator, a primary device into the patient's vasculature, wherein theprimary device is configured to perform a treatment.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages are described belowwith reference to the drawings, which are intended to illustrate, butnot to limit, the invention. In the drawings, like characters denotecorresponding features consistently throughout similar embodiments.

FIG. 1 illustrates a diagrammatic view of a patient undergoing aprocedure for removal of a thrombus using an elongated access assistdevice, according to some embodiments.

FIG. 2 illustrates a perspective view of a distal portion of anelongated access assist device, according to some embodiments.

FIG. 3 illustrates a perspective view of a proximal portion of anelongated access assist device, according to some embodiments.

FIGS. 4 and 5 illustrate schematic representations of a catheter system,according to some embodiments.

FIGS. 6, 7, 8, 9, 10, 11, 12, and 13 illustrate perspective views of acatheter system including a plurality of microperforations, according tosome embodiments.

FIGS. 14 and 15 illustrate perspective views of a working length of acatheter system, according to some embodiments.

FIGS. 16 and 17 illustrate perspective views of a taper length of atapered portion of an elongated access assist device, according to someembodiments.

FIG. 18 illustrates a perspective view of an elongated access assistdevice including a guidewire lumen, according to some embodiments.

FIGS. 19 and 20 illustrate front perspective views of an elongatedaccess assist device, according to some embodiments.

FIGS. 21, 22, and 23 illustrate perspective views of a neurovascularsheath tracked over an elongated access assist device, according to someembodiments.

FIGS. 24, 25, and 26 illustrate perspective views of a neurovascularaspiration catheter tracked over an elongated access assist device,according to some embodiments.

FIGS. 27, 28, 29, 30, 31, 32, and 33 illustrate perspective views of anelongated access assist device including a hydrophilic coating,according to some embodiments.

FIGS. 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, and 47illustrate perspective views of a tapered portion of an elongated accessassist device including at least one marker band, according to someembodiments.

FIG. 48 illustrates a perspective view of a vasculature navigationsystem, according to some embodiments.

FIG. 49 illustrates a perspective view of a vasculature navigationsystem including a hydrophilic coating and a plurality ofmicroperforations, according to some embodiments.

FIGS. 50A and 50B illustrate layers of a dilator of a vasculaturenavigation system, according to some embodiments.

FIG. 51 illustrates a side view of a dilator of a vasculature navigationsystem including a plurality of microperforations, according to someembodiments.

COMPONENT INDEX

-   -   10— catheter system    -   12— elongated access assist device    -   14— proximal end    -   16— distal end    -   18— guidewire lumen    -   20— proximal portion    -   22— distal portion    -   24— access port    -   26— guidewire    -   28— distal port    -   30— hemostasis valve    -   31— port    -   32— flush port    -   34— fluid supply source    -   36— tapered portion    -   38— outer surface (of tapered portion)    -   40— plurality of microperforations    -   42— fluid    -   44— marker band    -   44a— first marker band    -   44b— second marker band    -   44c— third marker band    -   46— distal tip    -   48— distance from distal tip    -   50— neurovascular sheath    -   52— inner diameter (of neurovascular sheath)    -   54— outer diameter (of access assist device)    -   56— neurovascular aspiration catheter    -   57— outer diameter (of access assist device)    -   58— inner diameter (of neurovascular aspiration catheter)    -   60— proximal outer diameter (tapered portion)    -   62— proximal inner diameter (tapered portion)    -   64— distal outer diameter (tapered portion)    -   66— distal inner diameter (tapered portion)    -   68— symmetrical conical shape    -   70— asymmetrical conical shape    -   71— asymmetrical conical shape    -   72— hydrophilic coating    -   74— exterior surface (of elongated access assist device)    -   76— working length    -   78— thrombus    -   80— patient    -   82— taper length    -   100— vasculature navigation system    -   102— dilator    -   104— proximal end    -   106— distal end    -   110— proximal portion    -   112— distal portion    -   114— access port    -   116— guidewire    -   120— hemostasis valve    -   122— flush port    -   123— fluid    -   124— fluid supply source    -   126— tapered portion    -   128— outer surface (of tapered portion)    -   130— plurality of microperforations    -   132— exterior surface (of dilator)    -   134— spiral configuration    -   136— hydrophilic coating    -   138— reinforcement structure    -   140— inner shaft    -   142— outer shaft    -   144— PTFE liner    -   146— inner PEBA layer    -   148a— first outer section    -   148b— second outer section    -   148c— third outer section    -   148d— fourth outer section    -   150— diameter

DETAILED DESCRIPTION

Although certain embodiments and examples are disclosed below, inventivesubject matter extends beyond the specifically disclosed embodiments toother alternative embodiments and/or uses, and to modifications andequivalents thereof. Thus, the scope of the claims appended hereto isnot limited by any of the particular embodiments described below. Forexample, in any method or process disclosed herein, the acts oroperations of the method or process may be performed in any suitablesequence and are not necessarily limited to any particular disclosedsequence. Various operations may be described as multiple discreteoperations in turn, in a manner that may be helpful in understandingcertain embodiments; however, the order of description should not beconstrued to imply that these operations are order dependent.Additionally, the structures, systems, and/or devices described hereinmay be embodied as integrated components or as separate components.

For purposes of comparing various embodiments, certain aspects andadvantages of these embodiments are described. All such aspects oradvantages are not necessarily achieved by any particular embodiment.For example, various embodiments may be carried out in a manner thatachieves or optimizes one advantage or group of advantages as taughtherein without necessarily achieving other aspects or advantages as mayalso be taught or suggested herein.

An objective of the present invention is to provide a catheter systemthat reduces shelf effect by providing a smooth and soft transitionbetween the distal edge of the access assist device and the conjunctiveprimary device (e.g., neurovascular sheath, guide catheter, aspirationcatheter, and the like).

FIG. 1 illustrates a diagrammatic view of a patient 80 undergoing aprocedure to remove a thrombus 78 using a catheter system 10. As shown,the system 10 may include an elongated access assist device 12 as wellas a guidewire 26, which may extend through an interior portion of theelongated access assist device 12. In many embodiments, the elongatedaccess assist device 12 includes an access port 24 and a flush port 32located adjacent a proximal end of the elongated access assist device12. As shown in FIG. 1 , the elongated access assist device 12 mayextend through an interior portion of a primary device, such as aneurovascular sheath 50, which is discussed further on with regards toFIG. 21 .

FIG. 1 shows the thrombus 78 located in a cranial region of the patient80. In some embodiments, the thrombus 78 is located in a region of theinternal carotid artery (“ICA”) or the middle cerebral artery (“MCA”) ofthe patient 80. The proximal end 14 of the elongated access assistdevice 12 is shown adjacent a groin region of the patient 80. In manyembodiments, the elongated access assist device 12 is inserted into thevasculature through an arteriotomy located in the common femoral arteryof the patient 80. The arteriotomy may be located in an artery otherthan the common femoral artery, though is usually located in a groin orleg region of the patient 80. In some embodiments, the arteriotomy islocated in the radial artery near the lower arm or wrist region of thepatient 80.

FIG. 2 shows a more detailed view of the elongated access assist device12 located in the vasculature near the thrombus 78. As demonstrated, inmany embodiments, a distal end 16 of the elongated access assist device12 comprises a tapered portion 36, which tapers down to a distal port28. Stated differently, an outer surface of the tapered portion 36tapers downward toward the distal end 16. The distal port 28 may enablethe removal of the thrombus 78 by providing an opening for the thrombus78 to enter the elongated access assist device 12 and exit the patient80 through the access port 24. In some embodiments, the elongated accessassist device 12 is retracted prior to removal of the thrombus 78.

The distal port 28 may also provide an opening for the guidewire 26 toprotrude from the distal end 16 of the elongated access assist device12. In some embodiments, the guidewire 26 extends beyond the distal end16 in order to facilitate navigation of the elongated access assistdevice 12 through the vasculature. The guidewire 26 may also beconfigured to puncture the thrombus 78. For example, in a mechanicalthrombectomy procedure, the guidewire 26 may be used to physically breakapart the thrombus 78 prior to, or simultaneously with, the applicationof aspiration (e.g., suction) to the elongated access assist device 12such that the fragments of the thrombus 78 are pulled through theelongated access assist device 12 via the aspiration force.Alternatively, an aspiration catheter may be used to remove the thrombus78. For example, the elongated access assist device 12 may be advancedto the face of the thrombus 78 while located at least partially within aprimary device, such as a sheath. The elongated access assist device 12may then be removed and replaced with a smaller elongated access assistdevice 12. The sheath may then be removed and replaced with andaspiration catheter, which is tracked over the smaller elongated accessassist device 12. Finally, upon removal of the smaller elongated accessassist device 12 from the aspiration catheter, the aspiration force maybe applied to the aspiration catheter to facilitate removal of thethrombus 78.

In many embodiments, the tapered portion 36 facilitates navigation ofthe elongated access assist device 12 throughout the vasculature,especially more tortuous sections such as the aortic arch, the commoncarotid arteries, the internal carotid arteries, the cerebral arteries,the ostium of the ophthalmic artery, and posterior neurovasculature. Itshould be noted that the cited arteries are included for example andform a nonlimiting list. The elongated access assist device 12 may beconfigured to navigate portions of the vasculature not specificallystated in this disclosure. In some embodiments, the tapered portion 36reduces the “shelf effect” discussed in the Background section of thisdisclosure by providing a smooth and soft transition between the distalend 16 of the elongated access assist device 12 and the conjunctiveprimary device (e.g., neurovascular sheath 50, guide catheter,aspiration catheter 56, and the like; not shown in FIG. 2 ). Differentprimary devices and the transition between the elongated access assistdevice 12 and each primary device will be shown in, and discussedfurther with reference to, FIGS. 21-26 . As shown in FIG. 2 , theelongated access assist device 12 extends through an interior portion ofa neurovascular aspiration catheter 56.

FIG. 3 shows a more detailed view of the proximal end 14 of theelongated access assist device 12, including the flush port 32, accessport 24, and hemostasis valve 30. In many embodiments, the proximal end14 is located opposite the distal end 16, shown in FIG. 2 . It should benoted that the access port 24 and the hemostasis valve 30 may beconsidered the same element of the elongated access assist device 12. Inother words, the hemostasis valve 30 may be integrated into theelongated access assist device 12, rather than a separate elementcoupled to the elongated access assist device 12. Accordingly, referenceto the access port 24 may also be considered reference to the hemostasisvalve 30, and vice versa. In some embodiments, the elongated accessassist device 12 does not include a hemostasis valve 30.

Though not shown in FIG. 3 , in many embodiments, the access port 24 isconfigured to receive the guidewire 26, which extends through the bodyof the elongated access assist device 12 and through the distal port 28,as shown in FIGS. 1 and 2 . The access port 24 may also be configured toreceive any other device inserted into the elongated access assistdevice 12, such as a microcatheter, dilator, and the like. In someembodiments, the flush port 32 is configured to couple to a fluid supplysource, which will be discussed in greater detail later in thedisclosure. As illustrated in FIG. 3 , the flush port 32 may be locateddistal to the hemostasis valve 30. In many embodiments, both the flushport 32 and the hemostasis valve 30 are located on a proximal portion,adjacent the proximal end 14, of the elongated access assist device 12.The flush port 32 may be configured to couple directly to the hemostasisvalve 30.

The hemostasis valve 30 may be configured to control fluid flow betweenthe proximal portion and the distal portion of the elongated accessassist device 12. For example, during a thrombectomy procedure, thehemostasis valve 30 may prevent backflow of blood from the distalportion out through the proximal portion of the elongated access assistdevice 12. In some embodiments, the hemostasis valve 30 comprises arotating seal configured to allow the insertion of the guidewire 26while reducing leakage of blood out of the access port 24 during theprocedure. The rotating seal may be loosened to allow movement of theguidewire 26, then tightened when the guidewire 26 is in the desiredlocation within the elongated access assist device 12 and/or thevasculature. In some embodiments, the rotating seal is threadablycoupled to the hemostasis valve 30. Any suitable type of seal other thana rotating seal may be used.

FIGS. 4 and 5 illustrate schematic representations of the cathetersystem 10, including some components of the elongated access assistdevice 12, the patient 80, the fluid supply source 34, and the thrombus78. FIG. 4 shows a schematic of an elongated access assist device 12 a,while FIG. 5 shows a schematic of another elongated access assist device12 b, including fewer components than the embodiment illustrated in FIG.4 . FIGS. 4 and 5 may be considered to show the “flow” of a device(e.g., guidewire) or fluid (e.g., saline) through the elongated accessassist device 12 a, 12 b. FIGS. 4 and 5 also illustrate the proximalportion 20 and distal portion 22 of the elongated access assist device12 a, 12 b, and which components are located in each portion, accordingto some embodiments. As such, the “flow” through the elongated accessassist device 12 a, 12 b illustrated in FIGS. 4 and 5 moves from themost proximal location to the most distal location.

For example, referring to FIG. 4 , fluid may flow from the fluid supplysource 34 through the flush port 32 of the elongated access assistdevice 12 a. As such, the elongated access assist device 12 may beconsidered to be in fluid communication with the fluid supply source 34.The access port 24 and flush port 32 are shown converging in thehemostasis valve 30, as, in some embodiments, the hemostasis valve 30comprises the flush port 32 and the access port 24. From the hemostasisvalve 30, the fluid may flow to and, for at least a portion of thefluid, through the plurality of microperforations 40. In someembodiments, the fluid flows through an annular space within theelongated access assist device 12.

The plurality of microperforations 40 are shown in both the proximalportion 20 and distal portion 22 of the elongated access assist device12 a because, in many embodiments, the plurality of microperforations 40are located in both portions 20, 22 of the elongated access assistdevice 12 a. The fluid remaining in the elongated access assist device12 a (i.e., the fluid that was not released through the plurality ofmicroperforations 40) continues in a distal direction through theelongated access assist device 12 a to the second marker band 44 b,which, in some embodiments, is located immediately proximal to thetapered portion 36. As the fluid moves through an interior portion ofthe elongated access assist device the fluid may pass by the secondmarker band 44 b through the tapered portion 36, whereby the fluidpasses by the first marker band 44 a, which, in some embodiments, islocated substantially immediately proximal to the distal tip 46. Asshown in FIGS. 1 and 2 , the distal tip 46 may be located adjacent thethrombus 78. The patient 80 is also included in FIG. 4 located adjacentthe proximal portion 20. In this context, the “patient 80” may beconsidered to represent an arteriotomy in the patient 80, where theelongated access assist device 12 a is inserted.

It should be noted that though the “flow” discussed with reference toFIG. 4 is discussed in terms of the flow of fluid, substantially thesame path may be taken by a guidewire 26, though the guidewire 26 wouldnot originate from the fluid supply source 34, enter the flush port 32,and thereby exit through the plurality of microperforations 40. Itshould also be noted that the fluid “meeting” the first and/or secondmarker bands 44 a, 44 b does not necessarily imply contact between thefluid and the marker bands 44 a, 44 b. For example, the fluid may flowthrough an interior portion of the elongated access assist device 12 awhile the first and second marker bands 44 a, 44 b are located on anexterior portion of the device 12 a. In some embodiments, the fluid doescome into contact with the first and/or second marker bands 44 a, 44 b,as the fluid is released through the plurality of microperforations 40on the surface of the elongated access assist device 12 a.

FIG. 5 illustrates a similar schematic representation as compared toFIG. 4 , but shows fewer components of the elongated access assistdevice 12 b. For example, the embodiment shown in FIG. 5 may onlyinclude one port 31, which may serve as either the access port 24, theflush port 32, or both. Furthermore, the embodiment shown in FIG. 5 mayomit a second marker band 44 b. As such, in some embodiments, theelongated access assist device 12 b includes only a single marker band,the first marker band 44 a. The elongated access assist device 12 b maynot differentiate between an access port 24 and the hemostasis valve 30,and therefore only include the hemostasis valve 30, as illustrated inFIG. 5 . It should also be noted that rather than being located in boththe proximal portion 20 and the distal portion 22, as demonstrated inFIGS. 4 and 5 , the plurality of microperforations 40 may be located ineither the proximal portion 20 or the distal portion 22. In someembodiments, the plurality of microperforations 40 are coupled to atleast the distal portion 22 of the elongated access assist device 12.Embodiments of the elongated access assist device 12 showing theplurality of microperforations 40 in different configurations aredepicted in FIGS. 6-13 .

Referring now to FIG. 6 , an embodiment of the catheter system 10 isshown. As illustrated, the system 10 may include an elongated accessassist device 12 comprising a proximal portion 20 and a distal portion22 located opposite the proximal portion 20. Though illustrated asunequal lengths, the proximal portion 20 may be the proximal half of theelongated access assist device 12 comprising approximately 50% of thelength, and the distal portion 22 may be the distal half of theelongated access assist device 12 comprising approximately 50% of thelength. In some embodiments, as shown in FIG. 6 , the proximal portion20 comprises less than half (e.g., 1% to 49%) of the working length ofthe elongated access assist device 12. As well, in some embodiments, theproximal portion 20 may comprise more than half (e.g., 51% to 99%) ofthe working length of the elongated access assist device 12.Accordingly, in some embodiments, the distal portion 22 comprises lessthan half (e.g., 1% to 49%) of the working length of the elongatedaccess assist device 12. And in some embodiments, the distal portion 22comprises more than half (e.g., 51% to 99%) of the working length of theelongated access assist device 12.

In some embodiments, the proximal portion 20 includes the access port 24and the flush port 32. As previously stated, the access port 24 maycomprise a hemostasis valve 30. As such, the proximal portion 20 mayalso include the hemostasis valve 30. In some embodiments, the distalportion 22 includes the tapered portion 36, the distal tip 46, the firstmarker band 44 a, and the second marker band 44 b. The guidewire 26 maybe configured to extend from the access port 24 to the distal tip 46,and through the distal port 28, as shown in FIG. 2 . In someembodiments, the elongated access assist device 12 comprises a guidewirelumen extending between the proximal end 14 and the distal end 16,wherein the guidewire lumen is configured to receive the guidewire 26.The guidewire lumen will be discussed in greater detail later in thedisclosure.

FIGS. 6-13 show the fluid supply source 34 coupled to the flush port 32.The fluid supply source 34 may be coupled to the flush port 32 vianumerous mechanisms, including a threadable coupling, a heat bondedcoupling, a friction fit, and/or the like. In many embodiments, thefluid supply source 34 is detachably coupled to the flush port 32. Thefluid supply source 34 may fixedly couple to the flush port 32. In someembodiments, the fluid supply source 34 is configured to couple to theaccess port 24, rather than the flush port 32. The fluid supply source34 may be configured to couple to both the access port 24 and the flushport 32. The fluid supply source 34 may couple to both the access port24 and the flush port 32 substantially simultaneously. In manyembodiments, the fluid 42 of the fluid supply source 34 comprises atleast one of saline, contrast dye, any type of bioabsorbable media, andthe like. The fluid 42 may comprise another substance used inthrombectomy procedures, such as a lytic agent. In some embodiments, thefluid 42 is released from the fluid supply source 34 and through theflush port 32 into the elongated access assist device 12 in asubstantially continuous manner. The fluid 42 may be released in acontrolled and/or restricted manner. In some embodiments, the fluid 42is released in a passive manner. At least one of the flush port 32 andthe fluid supply source 34 may include a mechanism to control the flowof fluid, such as a pressure-activated valve.

As discussed with reference to FIGS. 4 and 5 , and as illustrated inFIG. 6 , the plurality of microperforations 40 may be located on boththe proximal portion 20 and the distal portion 22. As also illustratedin FIG. 6 , the plurality of microperforations 40 may be located on boththe body and the tapered portion 36 of the elongated access assistdevice 12. As illustrated in FIG. 7 , the plurality of microperforations40 may be located only on the body of the elongated access assist device12. In some embodiments, as shown in FIG. 8 , the plurality ofmicroperforations 40 are located only on the tapered portion 36. Theplurality of microperforations 40 may be substantially evenly spaced anddispersed across the tapered portion 36. FIG. 9 illustrates that theplurality of microperforations 40 may be located in two distinct areasof the elongated access assist device 12, such as on the tapered portion36 and another area on the body of the device 12, as shown. In someembodiments, as demonstrated by FIG. 10 , the plurality ofmicroperforations 40 are located in more than two distinct areas of theelongated access assist device 12. FIG. 11 illustrates that theplurality of microperforations 40 may be located on the tapered portion36 and on part of the body of the elongated access assist device 12.FIG. 11 shows the plurality of microperforations 40 extending proximallyfrom the tapered portion 36, but still on the distal portion 22 of thedevice 12, such that the plurality of microperforations 40 cover acontinuous section of the device 12, rather than two distinct areas, asshown in FIG. 9 . In some embodiments, as illustrated in FIG. 12 , theplurality of microperforations 40 extend along the elongated accessassist device 12 in at least one substantially straight line. FIG. 13shows that the plurality of microperforations 40 may extend along theelongated access assist device 12 in small clusters, rather than astraight line or even dispersion.

It should be noted that the embodiments shown in FIGS. 6-13 include onlysome of the possible arrangements of the plurality of microperforations40 on the elongated access assist device 12. Other arrangements mayinclude: a single straight line of microperforations, a wavy line ofmicroperforations, multiple wavy lines of microperforations, a corkscrewspiral of microperforations, microperforations on only a portion of thetapered portion 36, microperforations on only a portion of the body ofthe device 12, microperforations on only one side of the device 12,unevenly dispersed microperforations, and any number of other possiblearrangements and/or combinations therein. The elongated access assistdevice 12 may include no microperforations. In many embodiments, eachmicroperforation of the plurality of microperforations 40 defines ashape and/or size similar to a pinhole. Each microperforation may defineany other suitable shape, such as triangular, rectangular, ovoid, andthe like.

In many embodiments, the plurality of microperforations 40 areconfigured to facilitate a substantially continuous release (i.e.,perfusion) of fluid 42. The release of fluid 42 may further aid innavigation through tortuous anatomy by reducing friction between thevasculature and the elongated access assist device 12. As previouslydiscussed, in many embodiments, the elongated access assist device 12 isconfigured to be slideably received by a primary device, such as aneurovascular sheath or aspiration catheter. The plurality ofmicroperforations 40, with the associated perfusion of saline or anotherfluid 42, may also reduce friction between the device 12 and the primarydevice, particularly during insertion and/or removal of the elongatedaccess assist device 12 from the primary device, and vice versa.

Referring now to FIGS. 14 and 15 , two embodiments of the cathetersystem 10 are shown. As indicated in FIG. 14 , the system 10 may definea working length 76 a. FIG. 15 shows that the system 10 may define aworking length 76 b that is different from the working length 76 a. Thefollowing table includes some possibilities for working lengths, but isintended to be nonlimiting. The system 10 may define a working lengthnot included in the following table. In addition, the following examplelengths may be considered approximate lengths. For example, the providedlength of 81 cm may be considered “about” 81 cm. As such, a workinglength between 80 cm and 82 cm may be considered “about” 81 cm. Itshould be noted that “working length” is intended to define the lengthof the elongated access assist device 12 from the access port 24 to thedistal tip 46.

Possible Working Lengths  81 cm  91 cm 106 cm 130 cm 133 cm 150 cm 160cm

FIGS. 16 and 17 show different embodiments of the tapered portion 36 ofthe elongated access assist device 12. FIG. 16 illustrates an embodimentwith a taper length 82 a, while FIG. 17 illustrates an embodiment with ataper length 82 b. As shown, the taper length 82 a may define a shorterlength than the taper length 82 b. Similar to the working lengths, thefollowing table includes some possibilities for taper lengths, but isintended to be nonlimiting. The tapered portion 36 may define a taperlength not included in the following table. In addition, the followingexample lengths may be considered approximate lengths. For example, theprovided length of 5 cm may be considered “about” 5 cm. As such, a taperlength between 4.75 cm and 5.25 cm may be considered “about” 5 cm. Thetapered portion 36 may define at least part of the distal portion 22,and generally comprises less than half of the elongated access assistdevice 12. In many embodiments, the taper length 82 a, 82 b is limitedto a shorter length (e.g., 1-5 cm). A longer taper extends further fromthe primary device, and may be more difficult to control and navigatethrough the vasculature. A relatively short taper length 82 a, 82 b mayprovide the ideal balance between having the smooth transition createdby the tapered portion 36, while still remaining close to the distaledge of the primary device and thus having the supportive structure and“pushing power” of the primary device.

Possible Taper Lengths 1 cm 2 cm 5 cm 10 cm  20 cm 

FIG. 18 illustrates an embodiment of the elongated access assist device12 including a guidewire lumen 18. As discussed with reference to FIG. 6, the elongated access assist device 12 may comprise a guidewire lumen18 extending between the proximal end 14 and the distal end 16, whereinthe guidewire lumen 18 is configured to receive the guidewire 26. Inmany embodiments, the guidewire lumen 18 is substantially centeredwithin the elongated access assist device 12. The guidewire lumen 18 maybe located off-center, such that it is closer to one side of theelongated access assist device 12 than another (i.e., asymmetric). Insome embodiments, the guidewire lumen 18 defines a constant diameter.The guidewire lumen 18 may define a varying diameter; for example, theguidewire lumen 18 may taper in a manner similar to the elongated accessassist device 12.

The following table includes some example inner diameters of theguidewire lumen 18, as well as the corresponding guidewire 26 outerdiameters. It should be noted that, similar to the two tables above, thelisted values represent only a few examples and are intended to benonlimiting. At least one of the guidewire 26 and the guidewire lumen 18may define diameters not included in the table. In addition, each sizeguidewire 26 is not limited to a specific size of guidewire lumen 18.For example, a 0.014″ guidewire 26 may be configured to be received by a0.016″ lumen 18, a 0.018″ lumen 18, or a 0.02″ lumen 18.

Guidewire OD Guidewire Lumen ID 0.018″  0.02″ 0.016″ 0.018″ 0.014″0.016″

FIG. 19 illustrates a front perspective view of the elongated accessassist device 12, including the guidewire lumen 18. FIG. 19 also showsan embodiment where the guidewire lumen 18 is tapered, as indicated bythe difference seen between the proximal inner diameter 62 and thedistal inner diameter 66. In some embodiments, the proximal innerdiameter 62 is the inner diameter of the guidewire lumen 18 throughoutthe body of the elongated access assist device 12. The distal innerdiameter 66 may be the inner diameter of the guidewire lumen 18 at thedistal-most portion of the tapered portion 36; for example, at thedistal tip 46 and/or distal port 28. FIG. 19 also includes the proximalouter diameter 60 and the distal outer diameter 64. Similar to theproximal inner diameter 62, the proximal outer diameter 60 may beconsidered the outer diameter of the elongated access assist device 12throughout the non-tapered body portion of the device 12. The distalouter diameter 64 may be considered the outer diameter at the distal tip46 and/or distal port 28. In some embodiments, the distal outer diameter64 is 0.023″ and the distal inner diameter 66 is 0.018″. The proximalinner diameter 62 may be 0.02″, and the proximal outer diameter 60 maybe 0.068″. Each of the listed diameters is included by way of exampleonly, and the disclosed invention is not in any way limited to thestated diameters.

FIG. 19 also indicates that the drawing shows a symmetrical conicalshape 68 a of the tapered portion 36. FIG. 20 is similar to FIG. 19 ,but shows that the tapered portion 36 defines an asymmetrical conicalshape 70 a. The embodiment illustrated in FIG. 20 may include similar,the same, or different diameters for the proximal outer diameter 60, theproximal inner diameter 62, the distal outer diameter 64, and/or thedistal inner diameter 66. The symmetrical and asymmetrical conicalshapes 68 a, 70 a will be discussed in greater detail later in thedisclosure.

FIG. 21 illustrates the concept of the elongated access assist device 12used in conjunction with a primary device, such as a neurovascularsheath 50. The primary device may be a device other than a neurovascularsheath 50, such as, but not limited to, a neurovascular aspirationcatheter (shown in FIGS. 24-26 ), a neurovascular distal accesscatheter, and/or a neurovascular guidecatheter. As previously discussed,in many embodiments, the elongated access assist device 12 is placedthrough the primary device, and is configured to extend beyond thedistal edge of the primary device, as shown in FIGS. 21 and 22 . Atleast the tapered portion 36 of the elongated access assist device 12may be configured to extend beyond the distal edge of the primarydevice.

In many embodiments, the elongated access assist device 12 defines anouter diameter 54 a and the neurovascular sheath 50 defines an innerdiameter 52 a, as shown in FIG. 21 . In order to maximize support of theneurovascular sheath 50 by the elongated access assist device 12, and tominimize the shelf effect created by the gap between the outer diameter54 a and the inner diameter 52 a, it may be ideal to reduce the size ofthe gap. For example, in many embodiments, the outer diameter 54 a ofthe elongated access assist device 12 may define a diameter thatcomprises about 90% of the inner diameter 52 a of the neurovascularsheath 50. The following table presents some example outer diameters forthe elongated access assist device 12 and inner diameters for a primarydevice. As with the previous tables, the values are included by way ofexample only and are intended to be nonlimiting. It should be noted, asindicated below the table, that the values in the table are calculatedbased on embodiments where the outer diameter of the elongated accessassist device 12 is 90% of the inner diameter of the primary device. Insome embodiments, the outer diameter encompasses a percentage other than90% of the inner diameter. For example, the outer diameter may be 85%,95%, 97%, 99%, etc. of the inner diameter.

OD Access Assist Device ID Primary Device*  0.08″ 0.089″ 0.079″ 0.088″0.071″ 0.079″ 0.068″ 0.076″ 0.065″ 0.072″ 0.064″ 0.071″ 0.061″ 0.068″0.057″ 0.063″ 0.054″  0.06″ 0.049″ 0.054″ 0.032″ 0.035″ 0.024″ 0.027″0.023″ 0.025″ *based on OD of access device = 90% of ID of primarydevice

FIG. 21 also includes the first marker band 44 a and the second markerband 44 b. In many embodiments, as illustrated in FIG. 21 , the firstmarker band 44 a is located adjacent the distal port 28 of the elongatedaccess assist device 12, and the second marker band 44 b is locatedsubstantially immediately proximal to the tapered portion 36. As such,the second marker band 44 b may be considered an indicator of the“beginning,” when moving in a distal direction, of the tapered portion36. The first marker band 44 a may also be considered coupled to thedistal tip 46 of the tapered portion 36, and the second marker band 44 bmay be considered coupled to the elongated access assist device 12proximal to the tapered portion 36. In many embodiments, both the firstmarker band 44 a and the second marker band 44 b comprise a radiopaquematerial. The first and second marker bands 44 a, 44 b will be discussedfurther with reference to FIGS. 34-47 .

FIG. 22 shows a similar embodiment of the elongated access assist device12 shown in FIG. 21 , but demonstrates different placement of the firstand second marker bands 44 a, 44 b. In the embodiment of FIG. 22 , thesecond marker band 44 b is located more distally as compared to thesecond marker band 44 b shown in FIG. 21 . As such, the second markerband 44 b in FIG. 22 is located further “down” the tapered portion 36,and may not serve as an indication of the “beginning” of the taperedportion 36. In contrast, the first marker band 44 a is located moreproximally as compared to the first marker band 44 a shown in FIG. 21 .As such, FIG. 22 shows that, in some embodiments, the first marker band44 a is slightly further removed from the distal tip 46 of the elongatedaccess assist device 12. The distance between the distal tip 46 and thefirst marker band 44 a will be discussed in greater detail withreference to FIGS. 34 and 35 .

In addition, FIG. 22 includes an outer diameter 54 b of the elongatedaccess assist device 12 and an inner diameter 52 b of the neurovascularsheath 50. In some embodiments, the outer diameter 54 b is differentfrom the outer diameter 54 a of FIG. 21 , and the inner diameter 52 b isdifferent from the inner diameter 52 a of FIG. 21 . As a nonlimitingexample, the outer diameter 54 a may define 0.079″ and the innerdiameter 52 a may define 0.088″, while the outer diameter 54 b maydefine 0.057″ and the inner diameter 52 b may define 0.063″. In someembodiments, the outer diameter 54 a and inner diameter 52 a definesmaller diameters than the outer diameter 54 b and inner diameter 52 b.

FIG. 23 shows a front perspective view, similar to FIGS. 19 and 20 , ofthe neurovascular sheath 50 tracked over the elongated access assistdevice 12. FIG. 23 also demonstrates, with greater clarity, thedifference between the outer diameter 54 a of the elongated accessassist device 12 and the inner diameter 52 a of the neurovascular sheath50. A small difference, such as the one shown in FIGS. 21-23 , resultsin a small gap between the device 12 and the sheath 50, therebyproviding a smooth transition from the tapered portion 36 of the device12 to the neurovascular sheath 50 to reduce the shelf effect. Theconical tip design of the tapered portion 36 also helps provide thesmooth transition and ease navigation and trackability of the cathetersystem 10 through tortuous anatomy. As previously discussed, theperfusion of saline through the plurality of microperforations 40 mayfurther ease navigation and trackability by reducing friction betweenthe system 10 and the vasculature, and also by reducing friction betweenthe elongated access assist device 12 and the primary device, such asthe neurovascular sheath 50. It should be noted that FIG. 23 illustratesa symmetrical conical shape of the tapered portion 36, though thetapered portion 36 may define an asymmetrical conical shape. The taperedportion 36 may define a non-conical tapered shape.

FIGS. 24-26 are similar to FIGS. 21-23 , but show a different primarydevice. Instead of a neurovascular sheath 50, FIGS. 24-26 demonstratethat, in some embodiments, the elongated access assist device 12 is usedin conjunction with a neurovascular aspiration catheter 56. Theneurovascular aspiration catheter 56 may define an inner diameter 58 a,while the elongated access assist device 12 may define an outer diameter57 a, as indicated in FIG. 24 . FIG. 25 shows another embodiment of thesystem 10 including the neurovascular aspiration catheter 56, and showsthat the device 12 may define an outer diameter 57 b and the catheter 56may define an inner diameter 58 b. Each of the outer diameter 57 a, theouter diameter 57 b, the inner diameter 58 a, and the inner diameter 58b may define diameters provided in the table above included with thediscussion of FIG. 21 . In some embodiments, at least one of the outerdiameter 57 a, the outer diameter 57 b, the inner diameter 58 a, and theinner diameter 58 b defines a diameter not provided in the table above.FIG. 25 , like FIG. 22 , also shows the first and second marker bands 44a, 44 b with adjusted locations as compared to FIG. 24 . FIG. 26 , likeFIG. 23 , shows a front perspective view of the neurovascular aspirationcatheter 56 tracked over the elongated access assist device 12, anddemonstrates the small gap between the device 12 and the catheter 56, asa result of the similar diameters 57 a and 58 a.

In many embodiments, the catheter system 10 includes a hydrophiliccoating 72 located on at least a portion of an exterior surface 74 ofthe elongated access assist device 12, as indicated by FIGS. 27-33 .Similar to the plurality of microperforations 40, the hydrophiliccoating 72 may be located on substantially the entire exterior surface74, as shown in FIGS. 27 and 28 , or may be located on one or multipleportions of the exterior surface 74. For example, FIG. 29 shows that thehydrophilic coating 72 may be located on only a body portion of theelongated access assist device 12, but not on the tapered portion 36. Insome embodiments, as illustrated in FIG. 30 , the hydrophilic coating 72is located only on an exterior surface 74 of the tapered portion 36 ofthe elongated access assist device 12. FIG. 31 shows the hydrophiliccoating 72 located on the tapered portion 36, as well as extendingproximally onto part of the body portion of the elongated access assistdevice 12. In some embodiments, as shown in FIG. 32 , the hydrophiliccoating 72 is located on two distinct portions of the elongated accessassist device 12. FIG. 33 shows that the hydrophilic coating 72 may belocated on more than two distinct portions of the elongated accessassist device 12. Of course, the embodiments shown in FIGS. 27-33demonstrate only a few possible arrangements of the hydrophilic coating72, and are not intended to be limiting embodiments.

In many embodiments, the hydrophilic coating 72 comprises a lubriciouscoating which further, along with the conical tip design, the salineperfusion, and the diameters of the elongated access assist device 12and the primary device, helps the catheter system 10 navigate throughtortuous anatomy to reach an occlusion site with minimized shelf effectalong the way.

FIGS. 34-47 illustrate different embodiments of the elongated accessassist device 12, including varying shapes of the tapered portion 36 andvarying numbers and sizes of marker bands. FIG. 34 shows an embodimentwhere the tapered portion 36 defines a symmetrical conical shape 68 a,similar to that shown in the previous Figures. FIG. 34 also shows thefirst marker band 44 a and second marker band 44 b located at what maybe considered the “typical” positions; where the first marker band 44 ais located adjacent the distal tip 46 and the second marker band 44 b islocated proximal (e.g., at the “beginning” of) the tapered portion 36.In contrast, FIG. 35 illustrates a substantially similar symmetricalconical shape 68 b, but shows the first marker band 44 a locatedproximally compared to the “typical” position and the second marker band44 b located distally compared to the “typical” position. As previouslystated, in many embodiments, the first and second marker bands 44 a, 44b comprise radiopaque material. In some embodiments, radiopaque materialis used for radiopacity and visualization of the device as the devicetracks through the neurovasculature during a procedure. The radiopaquematerial may comprise at least one of platinum and iridium. In someembodiments, both the first and second marker bands 44 a, 44 b compriseplatinum. Both the first and second marker bands 44 a, 44 b may compriseiridium. One marker band 44 a or 44 b may comprise platinum while theother marker band 44 b or 44 a comprises iridium. Either or both of thefirst and second marker bands 44 a, 44 b may comprise a combination ofplatinum and iridium, or may comprise a different radiopaque material.

FIGS. 34 and 35 also illustrate the distance of the marker band 44 afrom the distal tip 46, indicated as distance from distal tip 48 a inFIG. 34 and distance from distal tip 48 b in FIG. 35 . In someembodiments, the first marker band 44 a is located adjacent the distaltip 46. The distance from distal tip 48 a may be about 0.5-1 mm, and thedistance from distal tip 48 b may be about 1-2 mm. The distance fromdistal tip 48 a may be smaller than 0.5 mm or larger than 1 mm. Thedistance from distal tip 48 b may be smaller than 1 mm or larger than 2mm.

FIGS. 36 and 37 illustrate other embodiments of the elongated accessassist device 12, where the tapered portion 36 defines an asymmetricalconical shape 70 a, 70 b. In some embodiments, the asymmetrical conicalshape 70 a, 70 b defines an offset shape where one side of the taperedportion 36 is straight and another side extends down at an angle fromthe body of the device 12 to the distal tip 46, as shown in FIGS. 36 and37 . FIGS. 36 and 37 also include the first and second marker bands 44a, 44 b, where FIG. 36 shows the marker bands 44 a, 44 b in the“typical” position, and FIG. 37 shows them in an adjusted position. Itshould be noted that though not shown in the Figures, at least one ofthe marker bands 44 a, 44 b may be located more proximally than justproximal to the tapered portion 36. For example, at least one of themarker bands 44 a, 44 b may be located on a body portion of theelongated access assist device 12 away from the tapered portion 36. Inmost embodiments though, at least one of the marker bands 44 a, 44 b islocated closer to the distal end 16 of the elongated access assistdevice 12 than the proximal end 14 of the elongated access assist device12.

FIGS. 38 and 39 show additional embodiments of the elongated accessassist device 12, where the tapered portion 36 defines an asymmetricalconical shape 71, 71 b. As illustrated, the asymmetrical conical shape71 a, 71 b is not quite the offset shape shown in FIGS. 36 and 37 , asboth sides of the tapered portion 36 are slanted. It should be notedthat the tapered portion 36 may define any number of shapes, includingshapes beyond those illustrated in the Figures. FIGS. 38 and 39 alsoinclude the first and second marker bands 44 a, 44 b, where FIG. 38 maybe considered to show the marker bands 44 a, 44 b in the “typical”position and FIG. 39 may be considered to show the marker bands 44 a, 44b in an altered position.

FIGS. 40 and 41 show further embodiments of the elongated access assistdevice 12, where the tapered portion 36 defines a symmetrical conicalshape 68 c, 68 d. In many embodiments, the symmetrical conical shapes 68a, 68 b, 68 c, and 68 d define substantially the same shape but theembodiments include differences regarding the marker bands 44 a, 44 b,and/or 44 c. For example, FIG. 34 shows the tapered portion 36 definingthe symmetrical conical shape 68 a, with the first and second markerbands 44 a, 44 b in the “typical” position. Similarly, FIG. 40 shows thetapered portion 36 defining the symmetrical conical shape 68 c with thefirst and second marker bands 44 a, 44 b in the “typical” position. FIG.40 also includes a third marker band 44 c, which is shown locatedbetween the first and second marker bands 44 a, 44 b. The third markerband 44 c may be located substantially evenly between the first markerband 44 a and the second marker band 44 b, as illustrated in FIGS. 40and 41 , or may be located closer to either the first marker band 44 aor the second marker band 44 b.

Similar to the first and second marker bands 44 a, 44 b, the thirdmarker band 44 c may comprise at least one of platinum and iridium. Insome embodiments, all three marker bands 44 a, 44 b, 44 c compriseplatinum. All three marker bands 44 a, 44 b, 44 c may comprise iridium.In some embodiments, two marker bands comprise platinum while the thirdcomprises iridium. Two marker bands may comprise iridium while the thirdcomprises platinum. At least one of the first, second, and third markerbands 44 a, 44 b, 44 c may comprise a combination of platinum andiridium. At least one of the first, second, and third marker bands 44 a,44 b, 44 c may comprise a different radiopaque material. At least one ofthe first, second, and third marker bands 44 a, 44 b, 44 c may comprisea combination of platinum, iridium, and/or a different radiopaquematerial.

FIGS. 42 and 43 illustrate embodiments of the elongated access assistdevice 12 where the tapered portion 36 defines an asymmetrical conicalshape 70 c, 70 d. Similar to the asymmetrical conical shape 70 a, 70 bshown in FIGS. 36 and 37 , the asymmetrical conical shape 70 c, 70 d maydefine an offset conical shape where one side extends substantiallystraight from the body portion of the elongated access assist device 12and the other side extends at an angle from the body toward the distaltip 46. Like FIGS. 40 and 41 , FIGS. 42 and 43 show embodimentscomprising a first marker band 44 a, a second marker band 44 b, and athird marker band 44 c. In some embodiments, the third marker band 44 cis located on the body of the elongated access assist device 12, ratherthan the tapered portion 36.

FIGS. 44 and 45 show embodiments of the elongated access assist device12 where the tapered portion 36 defines an asymmetrical conical shape 71c, 71 d, which may be substantially similar to the asymmetrical conicalshape 71 a, 71 b illustrated in FIGS. 38 and 39 . Like FIGS. 40-43 ,FIGS. 44 and 45 illustrate that, in some embodiments, the elongatedaccess assist device 12 comprises a third marker band 44 c in additionto the first marker band 44 a and second marker band 44 b. In someembodiments, the elongated access assist device 12 comprises more thanthree marker bands. The elongated access assist device 12 may comprise asingle marker band 44, as demonstrated in FIG. 46 . In some embodiments,the single marker band 44 comprises substantially the entire taperedportion 36 of the device 12. The single marker band 44 may be smallerthan illustrated in FIG. 46 , such that the marker band 44 takes up asmaller portion of the tapered portion 36. For example, the marker band44 may be configured to cover a distal half of the tapered portion 36.The marker band 44 may be configured to cover a proximal half of thetapered portion 36. In some embodiments, the marker band 44 isconfigured to cover a central portion of the tapered portion 36. Themarker band 44 may also be larger than illustrated in FIG. 46 , suchthat the marker band 44 takes up substantially all of the taperedportion 36 and at least a portion of the body of the elongated accessassist device 12.

FIG. 47 demonstrates that the first and second marker bands 44 a, 44 bmay define a different size than shown in the previous Figures. Forexample, as shown in FIG. 47 , the first and second marker bands 44 a,44 b may be wider than the first and second marker bands 44 a, 44 bshown, for example, in FIGS. 34-45 . The first and second marker bands44 a, 44 b may also be narrower than the first and second marker bandsshown in FIGS. 34-45 . In some embodiments, the first marker band 44 ais wider than previously depicted while the second marker band 44 b isnarrower than previously depicted, or vice versa. On any givenembodiment of the elongated access assist device 12, the first, second,and third marker bands 44 a, 44 b, 44 c are not necessarily the samesize. Similar to how two or all three of the marker bands 44 a, 44 b, 44c may comprise the same material, two or all three of the marker bands44 a, 44 b, 44 c may define the same size. In some embodiments, each ofthe first marker band 44 a, the second marker band 44 b, and the thirdmarker band 44 c define a different size and/or comprise a differentmaterial.

FIG. 48 illustrates an embodiment of a vasculature navigation system100. It should be noted that the vasculature navigation system 100 maybe similar to the catheter system 10 shown in FIGS. 1-47 and previouslydiscussed in this disclosure. For example, as shown in FIG. 48 , thevasculature navigation system 100 may include an access port 114, aflush port 122, a hemostasis valve 120, and a fluid supply source 124that may be substantially the same as the access port 24, flush port 32,hemostasis valve 30, and fluid supply source 34 of the catheter system10. In addition, the vasculature navigation system 100 may include aguidewire 116 and a tapered portion 126 substantially similar to theguidewire 26 and tapered portion 36 of the catheter system 10. Moreover,FIG. 48 includes parallel broken lines extending along the center of thedilator 102, which illustrate the location and/or path of the guidewire116 along the internal portion of the dilator 102.

In some embodiments, as illustrated in FIG. 48 , the vasculaturenavigation system 100 comprises a dilator 102 having a proximal end 104and a distal end 106 located opposite the proximal end 104. Thevasculature navigation system 100 may include a guidewire lumenextending between the proximal end 104 and the distal end 106, whereinthe guidewire lumen is configured to receive the guidewire 116. In someembodiments, the guidewire lumen is also configured to receive fluid 123from the fluid supply source 124, as will be discussed further withreference to FIG. 49 . The dilator 102 may also include a proximalportion 110 and a distal portion 112 located opposite the proximalportion 110, as shown in FIG. 48 . In some embodiments, and similar tothe catheter system 10, the proximal portion 110 includes an access port114 configured to receive the guidewire 116, a hemostasis valve 120configured to control fluid flow between the proximal portion 110 andthe distal portion 112, and a flush port 122 located distal to thehemostasis valve 120 and configured to couple to the fluid supply source124. The distal portion 112 may include a distal port located at thedistal end 106 and configured to further receive the guidewire 116, asillustrated in FIG. 48 .

The dilator 102 may also include a tapered portion 126 defining at leastpart of the distal portion 112 of the dilator 102. In some embodiments,an outer surface 128 of the tapered portion 126 tapers down toward thedistal end 106. The tapered portion 126 may define a symmetrical,conical shape, similar to the tapered portion 36 illustrated in FIGS.34, 35, 40, 41, 46 and 47 . In some embodiments, the tapered portion 126defines a short length. For example, the tapered portion 126 may definea length of about 3-5 mm. The tapered portion 126 may define a greaterlength, for example 1, 2, 5, 10, or 20 cm, as previously discussed inthis disclosure. The tapered portion 126 may define a length of lessthan 3 mm. The tapered portion 126 may define a length between 5 mm and1 cm. In some embodiments, the tapered portion 126 includes a rounded,or “bull-nose” tip, rather than a blunt tip.

FIG. 49 is similar to FIG. 48 , and includes additional elements of thevasculature navigation system 100. For example, in some embodiments, thesystem 100 includes a plurality of microperforations 130 coupled to atleast a portion of an exterior surface 132 of the dilator 102, includinga “back” surface of the dilator 102, as indicated by themicroperforations shown in dashed lines. As illustrated in FIG. 49 , theplurality of microperforations 130 may be located between the proximalportion 110 and the distal portion 112. In some embodiments, theplurality of microperforations 130 are located more on the proximalportion 110, closer to the proximal end 104 than the distal end 106. Insome embodiments, the plurality of microperforations 130 are locatedmore on the distal portion 112, closer to the distal end 106 than theproximal end 104. The plurality of microperforations 130 may be locatedsubstantially at a central portion of the dilator 102, in terms of theworking length. Each microperforation of the plurality ofmicroperforations 130 may define an aperture, or simple hole or opening,without a valve or other sort of mechanism obstructing and/or coveringeither an internal or external portion of each microperforation.

In some embodiments, the plurality of microperforations 130 areconfigured to release fluid 123 from the fluid supply source 124. Thefluid 123 may be released through the plurality of microperforations 130in a substantially continuous flow. In some embodiments, the fluid 123is released in discrete bursts, such as in separate ejections, waves,and the like. The system 100 may include a valve coupled to at least oneof the flush port 122 and the fluid supply source 124, the valvecomprising a pressure activated valve configured to control fluid flowfrom at least one of the flush port 122 and the fluid supply source 124.The valve may be configured to prevent backflow and/or entrance of airif the fluid supply source 124 becomes disconnected.

The fluid supply source 124 may be pressurized. In some embodiments, thefluid supply source 124 is pressurized to an extent sufficient to enablepropulsion of the dilator 102 upon release of fluid 123 via theplurality of microperforations 130. The fluid 123 may, in turn, bepressurized within the dilator 102 to the extent sufficient to enablepropulsion. In some embodiments, at least one of the fluid 123 and thefluid supply source 124 is pressurized to about 300 psi. The fluid 123may comprise saline. The release of fluid 123 through the plurality ofmicroperforations 130 may also help keep the dilator 102 centered withinthe vasculature (e.g., within a particular blood vessel) of the patient.

In some embodiments, the fluid 123 comprises a therapeutic agentreleased to provide treatment, rather than propulsion. For example, whenthe vasculature navigation system 100 is used during a neurological orvascular procedure, the fluid 123 may comprise heparinized saline. Thefluid 123 may comprise other medication and/or therapeutic agents, likewarm saline, cold saline, and contrast dye, to name a few. In someembodiments, the fluid 123 is configured to provide both propulsion andtherapeutic effect.

FIG. 49 also illustrates that, in some embodiments, the system 100comprises a hydrophilic coating 136 located on the distal portion 112 ofthe dilator 102. The hydrophilic coating 136 may be configured to reducefriction between the dilator 102 and the patient's vasculature. In someembodiments, the combination of the plurality of microperforations 130and the hydrophilic coating 136 is also configured to enable navigationof the dilator 102 through the patient's vasculature by reducingfriction between the dilator 102 and the patient's vasculature. Asillustrated in FIG. 49 , the plurality of microperforations 130 may belocated just proximal to the hydrophilic coating 136 such that the fluid123 released from the plurality of microperforations 130 is configuredto flow distally over the hydrophilic coating 136. In some embodiments,substantially continuous lubrication of the hydrophilic coating 136, bythe fluid 123, enables better navigation of the dilator 102. It shouldbe noted that the guidewire lumen may be configured to receive theguidewire 116 and fluid 123 simultaneously, such that the guidewire 116may be used to assist navigation of the dilator 102 while the fluid 123is released from the plurality of microperforations 130. Similar to FIG.48 , FIG. 49 includes dashed parallel lines representing the location ofthe guidewire 116 within an interior of the dilator 102.

In some embodiments, the hydrophilic coating 136 is configured to coverat least a portion of the distal portion 112 of the dilator 102,including the tapered portion 126. The hydrophilic coating 136 may coverthe distal 10 cm of the dilator 102. In some embodiments, thehydrophilic coating 136 is configured to cover the distal 20 cm of thedilator 102. The hydrophilic coating 136 may cover a portion of thedistal portion 112 less than 10 cm long. The hydrophilic coating 136 maycover a portion of the distal portion 112 greater than 20 cm long. Thehydrophilic coating 136 may cover a portion of the distal portion 112between 10 and 20 cm long. It should be noted that the distal portion112 and the proximal portion 110 may define unequal lengths. Forexample, the distal portion 112 may be considered the distalmost 20 cmof the dilator 102, while the proximal portion 110 may be considered theremaining 140 cm of the dilator 102, in an embodiment where the totalworking length of the dilator 102 is 160 cm. Stated another way, theterms “proximal portion 110” and “distal portion 112” should notnecessarily be interpreted as “proximal half” and “distal half” Thedistal portion 112 may also be defined as the area including thehydrophilic coating 136, while the proximal portion 110 “starts” withthe plurality of microperforations 130 and extends to the proximal end104.

Similar to the elongated access assist device 12 of the catheter system10, the dilator 102 may be configured to be received by a primarydevice. In some embodiments, when the dilator 102 is received by aprimary device, at least the tapered portion 126 extends distal a distalend of the primary device. The tapered portion 126 and a portion of thenon-tapered distal portion 112 may be configured to extend from theprimary device. In some embodiments, the hydrophilic coating 136 on thedilator 102 is configured to reduce friction between the dilator 102 andthe primary device. Similar to reducing friction in vasculature, thecombination of the plurality of microperforations 130 and thehydrophilic coating 136 may also reduce friction between the dilator 102and the primary device, especially during insertion and/or removal ofthe dilator 102 from the primary device.

Primary devices may include, but are not limited to, guide catheter(s),aspiration catheter(s), sheath(s), delivery catheter(s) and/or any kindof treatment catheter used within a patient's vasculature to deploystents, treat blood clots, and/or any number of other uses. Thepotential uses of the vasculature navigation system 100 are not limitedto any particular type of procedure or part of the body, and may be usedto generally improve trackability with any catheter through thepatient's body. For example, the system 100 may be useful for removingblood clots from either or both lungs by entering the patient throughthe leg or groin and navigating to a pulmonary artery. The system 100may also be used in a radial approach to a patient's kidneys, bowel,liver, and/or other abdominal organs. The system 100 can also be used totreat atherosclerosis in the extremities. The system 100 may navigatethrough venous and arterial systems throughout the body, including, butnot limited to, cardiac systems, abdominal systems, and neurovascularsystems. In many cases, traditional treatment options for a number ofdiagnoses—including pulmonary emboli, aortic steno sis, andatherosclerosis, among others—require the use of large catheters thatare often difficult to navigate, especially through small vessels andtortuous anatomy. The system 100 enables better navigation todifficult-to-reach treatment locations, and, in some embodiments, isconfigured for use with many traditional types/models of catheters. Thefollowing table represents some different size embodiments of thedilator 102 and indicates which current catheter model is compatible. Itshould be noted that “outer diameter” refers to the outer diameter ofthe dilator 102 along substantially the entire length other than thetapered portion 126.

Outer Diameter Length Compatible Catheters 0.057″ 160 cm Stryker ® CAT ™6 Penumbra ® ACE ™ 60 Penumbra ® RED ™ 62 Microvention ® SOFIA ™ 5Fr0.068″ 160 cm Stryker ® Vecta ™ 74 Medtronic ® React ™ 71 Penumbra ®JET ™ 7 Imperative ™ Care Zoom ™ 71 Ceronovus ® LBC 0.085″ 132 cmPenumbra ® Neuron MAX ® Penumbra ® BENCHMARK ™ BMX ™ Balt ® Ballast ™Cook Medical ® Flexor ® Shuttle ® 0.095″ 160 cm Penumbra ® CAT ™ 8Indigo ® System Cook Medical ® 8Fr Flexor ® Ansel Sheath  0.12″ 160 cm10Fr thrombectomy systems 10Fr delivery sheaths  0.15″ 160 cm Penumbra ®CAT ™ 12 Indigo ® System

The dimensions in the table above are included as nonlimiting examples.In some embodiments, the length of the dilator 102 defines a lengthother than 132 cm or 160 cm. The dilator 102 may be longer than 160 cm,shorter than 132 cm, or between 132 and 160 cm. The dilator 102 may alsodefine an outer diameter other than the example dimensions included inthe table. In some embodiments, the dilator 102 defines an outerdiameter of 0.055 inches. The guidewire 116 may define a diameter of0.013 inches. The guidewire 116 may define a diameter of 0.014 inches.In some embodiments, the guidewire 116 defines a diameter larger than0.014 inches, such as 0.035 inches. The guidewire 116 may define adiameter between 0.014 inches and 0.035 inches, or greater than 0.035inches. In some embodiments, the inner diameter of the dilator 102(i.e., the guidewire lumen) is 0.018 inches. The inner diameter may beconsistent throughout the length of the dilator 102, such that eventhough the outer diameter decreases at the tapered portion 126, theinner diameter is the same at the proximal end 104 and the distal end106. As indicated by the inner and outer diameter dimensions, in someembodiments, the dilator 102 comprises a thick-walled diameter.

As previously discussed in this disclosure with reference to thecatheter system 10, the elongated access assist device 12 may be sizedto provide support to the primary device, as well as reduce shelfeffect. Similarly, the dilator 102 may be sized to provide support toany of the primary devices shown in the table above, as well as toreduce shelf effect. In many embodiments, the dilator 102 defines anouter diameter, as shown in the table, and the primary device defines aninner diameter. In order to maximize support of the primary device bythe dilator 102, and to minimize the shelf effect created by the gapbetween the outer diameter and the inner diameter, it may be ideal toreduce the size of the gap. For example, in some embodiments, the outerdiameter of the dilator 102 defines a diameter that comprises about 90%of the inner diameter of the primary device. The outer diameter of thedilator 102 may encompass a percentage other than 90% of the innerdiameter. For example, the outer diameter may be 85%, 95%, 97%, 99%,etc. of the inner diameter.

In some embodiments, the outer diameter of the dilator 102 is about 95%of the inner diameter of the primary device. In some embodiments, theouter diameter of the dilator 102 is about 91% of the inner diameter ofthe primary device. In some embodiments, the outer diameter of thedilator 102 is about 92% of the inner diameter of the primary device. Insome embodiments, the outer diameter of the dilator 102 is about 93% ofthe inner diameter of the primary device. In some embodiments, the outerdiameter of the dilator 102 is about 94% of the inner diameter of theprimary device. In some embodiments, the outer diameter of the dilator102 is about 96% of the inner diameter of the primary device. In someembodiments, the outer diameter of the dilator 102 is about 97% of theinner diameter of the primary device. In some embodiments, the outerdiameter of the dilator 102 is about 98% of the inner diameter of theprimary device. In some embodiments, the outer diameter of the dilator102 is about 99% of the inner diameter of the primary device. In someembodiments, the outer diameter of the dilator 102 is about 99.9% of theinner diameter of the primary device. The inner diameter may be a wholepercentage (e.g., 95%) of the outer diameter. In some embodiments, theinner diameter is a tenth of a percentage (e.g., 95.4%) of the outerdiameter.

Referring now to FIGS. 50A and 50B, different layers of the dilator 102are shown. As illustrated in FIG. 50A, in some embodiments, the dilator102 comprises a coaxial design including an inner shaft 140 and an outershaft 142. The inner shaft 140 may comprise two layers—a PTFE liner 144and an inner polyether block amide (PEBA) layer 146. It should be notedthat, though not illustrated in FIG. 50B, both the PTFE liner 144 andthe inner PEBA layer 146 may be configured to extend substantially thefull length of the dilator 102, within the outer shaft 142. In someembodiments, the PTFE liner 144 contributes lubricity to the dilator 102to ease loading and/or movement of the guidewire 116 within the dilator102 by reducing friction between the guidewire 116 and the dilator 102.The inner PEBA layer 146 may be thought of as a “jacket” that covers thePTFE liner 144, adding support and structural integrity to the innershaft 140 while maintaining an appropriate degree of softness andflexibility. The inner PEBA layer 146 may also increase the kinkresistance of the dilator 102. In some embodiments, the outer diameterof the inner shaft 140 is about 0.024-0.025 inches.

As illustrated in FIG. 50A, the dilator 102 may also comprise areinforcement structure 138 located within a wall of the dilator 102. Insome embodiments, the reinforcement structure 138 defines a coil shapeand is wound over the PTFE liner 144. The inner PEBA layer 146 and outershaft 142 may then be coated over the reinforcement structure 138 suchthat the structure 138 is substantially enclosed within the wall of thedilator 102. The reinforcement structure 138 may not be fully enclosedwithin the wall, and at least a portion of the structure 138 may bepresent on an outer diameter of the inner PEBA layer 146 on an innerdiameter of the outer shaft 142. In some embodiments, the reinforcementstructure 138 is located within substantially an entire length of thedilator 102. The reinforcement structure 138 may terminate at a locationproximal to the tapered portion 126, such that the reinforcementstructure 138 is not located in a distalmost tip of the dilator 102. Insome embodiments, the reinforcement structure 138 comprises a roundwire.

FIG. 50B demonstrates that, in some embodiments, the outer shaft 142comprises a first outer section 148 a, a second outer section 148 b, athird outer section 148 c, and a fourth outer section 148 d. Unlike thelayers of the inner shaft 140, which comprise true layers where theinner PEBA layer 146 is coated on top of the PTFE liner 144, each of theouter sections 148 may represent a change in material along the lengthof the outer shaft 142. Stated differently, rather than layering on topof one another, each of the sections 148 may be located adjacent oneanother. There may be some minimal layering at the transition pointsbetween sections 148. The outer shaft 142 may define a substantiallyconsistent outer diameter throughout the proximal portion 110 and thedistal portion 112 until just proximal the tapered portion 126. Itshould be noted that the first outer section 148 a may be considered themost proximal section, while the fourth outer section 148 d may beconsidered the most distal section. For the sake of clarity of thedrawings, the tapered portion 126 is not included in FIGS. 50A and 50B.

In some embodiments, each of the first, second, and third outer sections148 a, 148 b, 148 c comprise PEBA material, like the inner PEBA layer146 of the inner shaft 140. The different sections 148 may bedistinguished based on the durometer grade of the PEBA of each section.For example, in some embodiments, the first outer section 148 acomprises 72D PEBA, the second outer section 148 b comprises 55D PEBA,and the third outer section 148 c comprises 35D PEBA. Like the secondouter section 148 b, the inner PEBA layer 146 may also comprise 55DPEBA. Each of the outer sections may also be distinguished based onlength. In some embodiments, the first outer section 148 a defines alength of about 140 cm, the second outer section 148 b defines a lengthof about 4 cm, and the third outer section 148 c defines a length ofabout 6 cm. The fourth outer section 148 d may define a length of about8 cm and may comprise a different polymer than PEBA. In someembodiments, the fourth outer section 148 d comprises a polyether orpolyester-based thermoplastic polyurethane (TPU) blend, such as aNEUSoft™ 62A TPU blend produced by Avient™. Any number of TPU blendsmade by different manufacturers may be suitable for creating the dilator102.

FIG. 51 illustrates a close-up view of the plurality ofmicroperforations 130 located on the exterior surface 132 of the dilator102. As shown in both FIGS. 49 and 51 , in some embodiments, theplurality of microperforations 130 is arranged in a spiral configuration134 around 360 degrees of the dilator 102. As previously mentioned, themicroperforations shown in dashed lines may be considered to representmicroperforations located on the “back” side of the dilator 102. Eachmicroperforation of the plurality of microperforations 130 may be evenlyspaced from an adjacent microperforation, and, in some embodiments, thespacing between microperforations is about 1 cm at a 90 degree angle.The spacing may comprise a distance greater than 1 cm. In someembodiments, the microperforations are closer to one another than 1 cm.The even spacing of the plurality of microperforations 130 maycontribute to a high degree of symmetry of the dilator 102.

In some embodiments, as shown in FIGS. 49 and 51 , the dilator 102includes a relatively small number of microperforations, especiallycompared to the plurality of microperforations 40 of the elongatedaccess assist device 12 of the catheter system 10. As illustrated in theFigures, the plurality of microperforations 130 may include fivemicroperforations. In some embodiments, the plurality ofmicroperforations 130 includes two, three, four, six, or more than sixmicroperforations.

Each microperforation of the plurality of microperforations 130 maydefine a diameter 150. In some embodiments, the diameter 150 is about0.01 inches. The diameter 150 may be slightly larger, such as 0.012inches. In some embodiments, the diameter 150 is smaller than 0.01inches. As a result of creating the plurality of microperforations 130via laser cutting the wall of the dilator 102, the plurality ofmicroperforations 130 may define a funnel shape, where the diameter onthe exterior surface 132 is larger than the diameter on the interiorsurface of the dilator 102.

It should be noted that though not illustrated with marker bands, thedilator 102 may comprise at least one marker band, similar to theelongated access assist device 12. The marker band(s) of the dilator 102may be located in a similar and/or the same location as the markerband(s) 44 of the elongated access assist device 12. For example, thetapered portion 126 may include at least one marker band.

Materials

With regard to the materials that comprise the various components of thecatheter system 10, a wide array of biocompatible materials may be used.For example, any one of Nylon 12, Copolyester, Polyolefin, Polyurethane,Polyether Block Amide, PTFE, Platinum, Iridium, Tungsten, and ahydrophilic coating may comprise any one or multiple components of thesystem 10. In addition, any one or multiple components of the system 10may comprise a combination of the listed materials. A person havingordinary skill in the art of medical devices, particularly neurovasculardevices, will understand that materials used in the system 10 mayinclude materials not listed in this disclosure. Materials used mayinclude a combination of any one or multiple listed materials with anyone or multiple materials not listed here.

Similar to the materials of the catheter system 10, a wide array ofbiocompatible materials may also be used to comprise the variouscomponents of the vasculature navigation system 100. Similar componentsbetween the two systems 10, 100 may be comprised of substantiallysimilar materials. In particular regarding the hydrophilic coating, aproprietary hydrophilic coating blend produced by Biocoat® (of Horsham,PA, USA) may be used. In some embodiments, the hydrophilic coating isapplied via a dip coating process and cured with UV light and/or heat.The hydrophilic coating may define a very thin layer over the outershaft 142 that does not significantly contribute to the outer diameterof the outer shaft 142. In some embodiments, the Biocoat® formulaoutperformed hydrophilic coatings from other producers, and was found tobe more durable with less flaking and a good lubricity that greatlyreduced the coefficient of friction.

None of the steps described herein is essential or indispensable. Any ofthe steps can be adjusted or modified. Other or additional steps can beused. Any portion of any of the steps, processes, structures, and/ordevices disclosed or illustrated in one embodiment, flowchart, orexample in this specification can be combined or used with or instead ofany other portion of any of the steps, processes, structures, and/ordevices disclosed or illustrated in a different embodiment, flowchart,or example. The embodiments and examples provided herein are notintended to be discrete and separate from each other.

The section headings and subheadings provided herein are nonlimiting.The section headings and subheadings do not represent or limit the fullscope of the embodiments described in the sections to which the headingsand subheadings pertain. For example, a section titled “Topic 1” mayinclude embodiments that do not pertain to Topic 1 and embodimentsdescribed in other sections may apply to and be combined withembodiments described within the “Topic 1” section.

The various features and processes described above may be usedindependently of one another, or may be combined in various ways. Allpossible combinations and subcombinations are intended to fall withinthe scope of this disclosure. In addition, certain method, event, state,or process blocks may be omitted in some implementations. The methods,steps, and processes described herein are also not limited to anyparticular sequence, and the blocks, steps, or states relating theretocan be performed in other sequences that are appropriate. For example,described tasks or events may be performed in an order other than theorder specifically disclosed. Multiple steps may be combined in a singleblock or state. The example tasks or events may be performed in serial,in parallel, or in some other manner. Tasks or events may be added to orremoved from the disclosed example embodiments. The example systems andcomponents described herein may be configured differently thandescribed. For example, elements may be added to, removed from, orrearranged compared to the disclosed example embodiments.

Conditional language used herein, such as, among others, “can,” “could,”“might,” “may,” “e.g.,” and the like, unless specifically statedotherwise, or otherwise understood within the context as used, isgenerally intended to convey that certain embodiments include, whileother embodiments do not include, certain features, elements and/orsteps. Thus, such conditional language is not generally intended toimply that features, elements and/or steps are in any way required forone or more embodiments or that one or more embodiments necessarilyinclude logic for deciding, with or without author input or prompting,whether these features, elements and/or steps are included or are to beperformed in any particular embodiment. The terms “comprising,”“including,” “having,” and the like are synonymous and are usedinclusively, in an open-ended fashion, and do not exclude additionalelements, features, acts, operations and so forth. Also, the term “or”is used in its inclusive sense (and not in its exclusive sense) so thatwhen used, for example, to connect a list of elements, the term “or”means one, some, or all of the elements in the list. Conjunctivelanguage such as the phrase “at least one of X, Y, and Z,” unlessspecifically stated otherwise, is otherwise understood with the contextas used in general to convey that an item, term, etc. may be either X,Y, or Z. Thus, such conjunctive language is not generally intended toimply that certain embodiments require at least one of X, at least oneof Y, and at least one of Z to each be present.

The term “and/or” means that “and” applies to some embodiments and “or”applies to some embodiments. Thus, A, B, and/or C can be replaced withA, B, and C written in one sentence and A, B, or C written in anothersentence. A, B, and/or C means that some embodiments can include A andB, some embodiments can include A and C, some embodiments can include Band C, some embodiments can only include A, some embodiments can includeonly B, some embodiments can include only C, and some embodiments caninclude A, B, and C. The term “and/or” is used to avoid unnecessaryredundancy.

The term “substantially” is used to mean “completely” or “nearlycompletely.” For example, the disclosure includes, “The plurality ofmicroperforations may be configured to facilitate a substantiallycontinuous release of fluid.” In this context, “substantiallycontinuous” means that the release of fluid may be continuous or nearlycontinuous. For example, there may be short (e.g., less than one minute)interruption(s) in fluid release during a procedure, and the release offluid would still be considered “substantially continuous.”

The term “about” is used to mean “approximately.” For example, indiscussing the outer diameter of the elongated access assist devicecompared to the inner diameter of a primary device, the disclosureincludes, “The outer diameter may be about 90% of the inner diameter.”In this context, “about 90%” is used to mean “approximately 90%.” Whendiscussing diameters, “about” may encompass+/−2% of the stated value.For example, an embodiment where the outer diameter is between 88% and92% of the inner diameter would fall into the understanding of “about90%,” as used in this disclosure.

The term “spaced” is used to mean “located at a distance from oneanother.” For example, the disclosure includes “the plurality ofmicroperforations are substantially evenly spaced and dispersed acrossthe tapered portion.” In this context, “spaced” indicates that eachmicroperforation in the plurality of microperforations is located at adistance from each other microperforation. Additionally, the use of“substantially evenly spaced” indicates that the microperforations areevenly spaced or nearly evenly spaced. An embodiment where the spacingbetween each microperforation is not exactly equal, but is within a 10%margin of error, would fall into the understanding of “substantiallyevenly spaced,” as used in this disclosure.

The term “dispersed” is used to mean “distributed or spread over a widearea.” For example, the disclosure includes, “the plurality ofmicroperforations are substantially evenly spaced and dispersed acrossthe tapered portion.” In this context, “dispersed” indicates that theplurality of microperforations are distributed or spread across thetapered portion, as shown in FIGS. 6 and 8-11 , as well as 28-33. Anembodiment where the plurality of microperforations are located on atleast 85% of the tapered portion would fall into the understanding of“dispersed across the tapered portion,” as used in this disclosure.

The term “adjacent” is used to mean “next to or adjoining.” For example,the disclosure includes, “In many embodiments, the elongated accessassist device 12 includes an access port 24 and a flush port 32 locatedadjacent a proximal end of the elongated access assist device 12.” Inthis context, the access port and flush port may be understood aslocated next to or adjoining the proximal end of the elongated accessassist device, as shown in FIG. 3 . For example, the access port may beconsidered adjoining the proximal end and the flush port may beconsidered next to the proximal end, but both are adjacent the proximalend.

The disclosure may refer to a “face of the occlusion.” In someembodiments, the “face of the occlusion” should be interpreted as the“site of the occlusion.” The “face of the occlusion” may also be used torefer simply to “the occlusion.”

The disclosure may refer to both an elongated access assist device and avascular navigation system. It should be appreciated that a vascularnavigation system may include an elongated access assist device. In someembodiments, the terms are used interchangeably. The disclosure mayinclude embodiments whereby the elongated access assist device isspecifically used in neurovascular treatment. Also, the disclosure mayinclude embodiments whereby the vascular navigation system isspecifically used in neurovascular treatment. Additionally, thedisclosure may include embodiments whereby the elongated access assistdevice is used in non-neurovascular treatments, e.g., cardiothoracictreatments, abdominal treatments, and treatments of a patient'sextremities. Moreover, the disclosure may include embodiments wherebythe vascular navigation system is used in non-neurovascular treatments,e.g., cardiothoracic treatments, abdominal treatments, and treatments ofa patient's extremities.

While certain example embodiments have been described, these embodimentshave been presented by way of example only, and are not intended tolimit the scope of the inventions disclosed herein. Thus, nothing in theforegoing description is intended to imply that any particular feature,characteristic, step, module, or block is necessary or indispensable.Indeed, the novel methods and systems described herein may be embodiedin a variety of other forms; furthermore, various omissions,substitutions, and changes in the form of the methods and systemsdescribed herein may be made without departing from the spirit of theinventions disclosed herein.

I claim:
 1. A method of navigating a dilator through a patient'svasculature, the method comprising: inserting, via an access site, thedilator into the patient's vasculature, wherein the dilator comprises anaccess port located at a proximal end of the dilator and configured toreceive a guidewire, a distal port located at a distal end of thedilator and configured to further receive the guidewire, a hemostasisvalve coupled to a proximal portion of the dilator and configured tocontrol fluid flow between the proximal portion and a distal portion, aflush port coupled to the proximal portion of the dilator, and aplurality of microperforations coupled to an exterior surface of thedilator; injecting fluid through the flush port; and releasing, via theplurality of microperforations, the fluid, wherein the plurality ofmicroperforations are arranged and configured such that the fluid isreleased adjacent a wall of the patient's vasculature.
 2. The method ofclaim 1, wherein the fluid comprises a therapeutic agent.
 3. The methodof claim 1, wherein injecting the fluid through the flush port isconfigured to pressurize the fluid to a pressure sufficient to enablepropulsion of the dilator upon release of the fluid through theplurality of microperforations.
 4. The method of claim 1, wherein thedilator comprises a hydrophilic coating located on the exterior surfaceof the dilator distal to the plurality of microperforations.
 5. Themethod of claim 4, further comprising lubricating, via the fluidreleased through the plurality of microperforations, the hydrophiliccoating.
 6. The method of claim 5, wherein lubricating the hydrophiliccoating comprises releasing, substantially continuously, the fluidthrough the plurality of microperforations.
 7. The method of claim 6,wherein the fluid comprises heparinized saline.
 8. The method of claim1, further comprising inserting, over the dilator, a primary device intothe patient's vasculature, wherein the primary device is configured toperform a treatment.
 9. A vasculature navigation system, comprising: adilator having a proximal end and a distal end located opposite theproximal end, the dilator comprising a guidewire lumen extending betweenthe proximal end and the distal end, the dilator defining a proximalportion and a distal portion located opposite the proximal portion; anaccess port located at the proximal end of the dilator, the access portconfigured to receive a guidewire; a distal port located at the distalend of the dilator, the distal port configured to further receive theguidewire; a hemostasis valve coupled to the proximal portion of thedilator, the hemostasis valve configured to control fluid flow betweenthe proximal portion and the distal portion; a flush port coupled to theproximal portion of the dilator and located distal to the hemostasisvalve; a tapered portion defining at least part of the distal portion ofthe dilator, wherein an outer surface of the tapered portion tapersdownward toward the distal end; and a hydrophilic coating located on anexterior surface of the dilator, wherein the hydrophilic coating enablesnavigation of the dilator through a patient's vasculature by reducingfriction between the dilator and the patient's vasculature.
 10. Thevasculature navigation system of claim 9, wherein the hydrophiliccoating is located on the distal portion of the dilator.
 11. Thevasculature navigation system of claim 10, wherein the hydrophiliccoating is located on the tapered portion of the dilator.
 12. Thevasculature navigation system of claim 9, further comprising: a fluidsupply source coupled to the flush port; and a fluid located within thefluid supply source and configured to flow from the fluid supply sourcethrough the flush port into the dilator.
 13. The vasculature navigationsystem of claim 12, further comprising a plurality of microperforationscoupled to an exterior surface of the proximal portion of the dilatorand configured to release the fluid from the fluid supply source. 14.The vasculature navigation system of claim 13, wherein the fluid isconfigured to flow distally from the plurality of microperforations overthe hydrophilic coating, thereby lubricating the hydrophilic coating.15. A vasculature navigation system, comprising: a dilator having aproximal end and a distal end located opposite the proximal end, thedilator comprising a guidewire lumen extending between the proximal endand the distal end, the dilator defining a proximal portion and a distalportion located opposite the proximal portion; an access port located atthe proximal end of the dilator, the access port configured to receive aguidewire; a distal port located at the distal end of the dilator, thedistal port configured to further receive the guidewire; a hemostasisvalve coupled to the proximal portion of the dilator, the hemostasisvalve configured to control fluid flow between the proximal portion andthe distal portion; a flush port coupled to the proximal portion of thedilator and located distal to the hemostasis valve; a tapered portiondefining at least part of the distal portion of the dilator, wherein anouter surface of the tapered portion tapers downward toward the distalend; and a plurality of microperforations located on an exterior surfaceof the dilator.
 16. The vasculature navigation system of claim 15,wherein the plurality of microperforations is located on the proximalportion of the dilator.
 17. The vasculature navigation system of claim15, wherein each microperforation of the plurality of microperforationsdefines an aperture.
 18. The vasculature navigation system of claim 15,further comprising: a fluid supply source coupled to the flush port; anda fluid located within the fluid supply source and configured to flowfrom the fluid supply source through the flush port into the dilator,wherein the plurality of microperforations is configured to release thefluid from the fluid supply source.
 19. The vasculature navigationsystem of claim 18, wherein the plurality of microperforations isconfigured to release a substantially continuous flow of fluid from thefluid supply source.
 20. The vasculature navigation system of claim 18,further comprising a hydrophilic coating located on an exterior surfaceof the dilator, wherein the plurality of microperforations and thehydrophilic coating enable navigation of the dilator through a patient'svasculature by reducing friction between the dilator and the patient'svasculature.